Detecting an acceleration applied to a vehicle to grasp the behavior of the vehicle is known. In recent years, mounting an acceleration sensor on a motorcycle has been proposed (for example, FIG. 1 of Japanese Patent Laid-Open No. 2015-123940).
As shown in FIG. 1(a) of Japanese Patent Laid-Open No. 2015-123940, in a saddle ride type vehicle (1) (the number in parentheses is a reference numeral in Japanese Patent Laid-Open No. 2015-123940, and the same applies hereinafter), a pivot support portion (12) is provided on the rear side of a frame (11). A swing arm (14) is attached to the pivot support portion (12) through a pivot member (13). A rear wheel (R) is attached to the rear side of the swing arm (14).
As shown in FIG. 1(c) of Japanese Patent Laid-Open No. 2015-123940, an acceleration sensor (20) is provided at the center of the pivot member (13) in the vehicle width direction. The attachment portion of the acceleration sensor (20) is limited because it is attached to the pivot member (13). Additionally, in the technique of Japanese Patent Laid-Open No. 2015-123940, a cover for protecting the acceleration sensor (20) is needed as a separate member, and the number of parts increases.
Hence, to omit the protective cover, the acceleration sensor is preferably arranged inside a vehicle body cover. In the motorcycle, however, since various parts are densely arranged, it is difficult to easily arrange the acceleration sensor inside the vehicle body cover. So, it is necessary to arrange the acceleration sensor inside the cover while reducing an influence on the arrangement of other parts.